The invention is concerned with apparatus for pumping fluid, such as the working fluid of a hydrodynamic adjustment coupling, and particularly pumping apparatus used for conducting fluid from the lower part of a machine housing (the sump) in which the fluid has collected into a container at a higher level.
The apparatus according to the present invention comprises a spinning disc which dips into the sump, and which has an axis of rotation that is sustantially horizontally. The spinning disc co-acts with a stationary supply duct disposed in the machine housing. The duct encloses at least approximately a quarter of the circumference of the spinning disc from the deepest point up to the vicinity of the horizontal center plane of the disc.
This type of pumping apparatus is known, for example, from British Pat. No. 1,064,007.
In the known pumping apparatus, the supply duct continues upward over one vertical side wall of the machine housing. At the upper end of the supply duct there are deflection means which conduct the supplied fluid to the higher level container.
There have been problems in designing such pumping apparatus in such a way that its through-put is satisfactory. In the known pumping apparatus, attempts have been made to achieve an adequate through-put by arranging a sheet metal ring laterally over the outer boundary of the spinning disc in such a way that an annular gap, which tapers in an outward direction, is located between the ring and the spinning disc.
In the known pumping apparatus it is necessary for the spinning disc to dip relatively deep down into the fluid collected in the sump. For this reason, the power absorbed by the spinning disc is relatively high.
A recommended field of application for pumping apparatus with spinning discs is in hydrodynamic adjustment couplings. There are couplings of the Foettinger design, with a variable filling level. For this purpose, in the revolving coupling shell, there are spraying nozzles, through which working fluid is continuously conducted away from the working chamber to the outside of the coupling. The working fluid collects in the sump of the coupling housing. It must be conducted from the sump into a higher level container from which the fluid can be supplied again to the working chamber of the coupling, via a control valve.
When the axis of rotation of such a hydrodynamic adjustment coupling is disposed horizontally, there is an opportunity to use a spinning disc as the pumping device for conducting the working fluid to the higher level container, since the disc can be attached to or formed on the revolving coupling shell. However, as already mentioned, the throughput of the spinning disc has not been satisfactory, and it has been found necessary to use other conventional pumps, such as rotary pumps or gear pumps, or to revert to the vertical arrangement of the axis of rotation of the coupling. In the latter vertical axis hydrodynamic adjustment coupling, it is possible to dispense with pumping apparatus. (See U.S. Pat. No. 3,999,385.)